Question: Solve for $x$ : $x - 19 = 30$
Explanation: Add $19$ to both sides: $ \begin{eqnarray} \\ x - 19 &=& 30 \\ \\ {+19} && {+19} \end{eqnarray} $ $ \begin{eqnarray} \hphantom{-19 + x} &\hphantom{=}& \hphantom{30} \\ x &=& 30 {+ 19} \\ \end{eqnarray} $ Simplify. $ x = 49$